Mast for drilling oil wells and the like



01:1. 22, 1940. D. MILLER 2,219,110

MAST FOR DRILLING OIL WELLS AND THE LIKE Filed Aug. 15, 1938 INVENTOR DEE MILLER ATTORNEY Patented Got. 22, 1940 urrs STATES,

MAST FOR, DRILLING 01L WELLS AND THE Dee Miller, Vandalia, .Ill., assignor to Perry A. Thayer, Wichita, Kans., and A. J. Boundy,

Salem, 111.

Application August 15, 1938, Serial No. 224,846

4 Claims This invention relates generally to drilling masts of the type used for drilling oil wells and the like, and more specifically to such a mast which is provided with a crown that is of such improved construction and is so arranged with respect to the leg portion of the mast that the cross bracing which is arranged between the legs of the mast may extend throughout the entire length of the leg portion of the mast from the extreme lower end of said leg portion to the extreme top thereof. By so arranging the cross bracing a very rigid leg structure is provided and the likelihood that the mastmay not be capable of withstanding the strains to which it is subjected in use is entirely eliminated.

Prior to this invention masts of the type to which this invention relates comprised a pairgof legs which converged from the lower end of the mast toward the upper end thereof. Adjacent to the upper end of the mast a shaft extended between the legs of the mast, from one leg to the other, and mounted on this shaft were sheaves which constituted the crown block of the mast. Because of this arrangement the drilling line operating over the crown'block was. disposed largely between the legs of the mast and so as to not interfere in any manner with the operation of the drilling line and to provide sufficient room for such operation of the drilling line the cross bracing between the legs had to be eliminated throughout practically the entire upper portion of the leg structure of the mast. This resulted in the production of a very weak mast structure which was not durable enough to withstand the very rough usage to which such masts are subjected.

In an attempt to move the drilling linefrom between the legs of the mast as much as possible so that more cross bracing might be arranged between the legs of the mast in the upper portion thereof, users of the masts heretofore employed resorted to the expedient of inclining the masts to a very decided degree. However this expedient caused the operators to be faced with more trouble as by inclining the mast to a point where some of the drilling line was withdrawn from between the legs of the mast to permit the use of more cross bracing between the mast legs the load carried by the mast was suspended far Outwardly at one side of the mast and therefore the guys extended from the opposite side of the mast were subjected to an excessive and dangerous load.

The prime object of this invention is to pro- .vide a mast which includes an improved crown that is mounted atop the legs of the mast in a balanced manner with portions of the crovvn overhanging the leg structure of the mast in opposite directions. The crown supports sheaves which constitute the crown block of the mast, one set of sheaves being supported by one overhanging portion of the crown so that they are disposed above and vertical line with the hole being drilled, and another set of sheaves being supported by the opposite'over'hanging portion of the crown so that the first-mentioned set of sheaves are balanced by the second-mentioned set of sheaves. Becauseof the disposition of the sets of sheaves of the crown block in overhanging relation with respectto the leg structure of'the mast the drilling line operating over the sheaves is located practically entirely outwardly of a position between the legs of the mast and therefore the cross bracingbetween the legs of the mast may extend from the lower ends to the upper ends of the mast legs.

Additionally because the crown with itsassociated crown block is supported in a balanced manner at the upper end of the leg structure of the mast the load carried by the mast when drill stems are supported by the mast, or raised or lowered with the aid thereof,.is so balanced and distributed with respect to the mast. structure that most of the load is carried by the mast structure itself and hence the guys of the mast are relieved-of much of the strain they were formerly required to bear when employed with masts of the construction and arrangement heretofore used.

Fig. l is a fragmentary side elevation of the improved mast, portions of the legs thereof being broken away to permit the mastto be illustrated on an enlarged scale.

Fig. 2 is a view partly in plan and partly in horizontal sections illustrating the crown of the improved mast;

Fig. 3 is a front elevation of the improved mast drawn on a reduced scale. 7

In the drawing, wherein is shown for the purpose of illustration, merely, one embodiment of the invention, A designates the improved mast generally. The mast A includes the usual skids l and rotary table 2, the latter serving ina well known manner to assist in subjecting the drill stems of rotary drills to rotary drilling movement. The mast A includes also a cross-beam 3 which is secured to the skids l, and legs 4' which are suitably attached to the cross-beam 3and extend upwardly therefrom. The legs of the mast-of the present invention are two in number Ill and the pair of legs converge toward each other from their lower ends which are located at the cross-beam 3 toward their upper ends as shown in Fig. 3. The leg structure of the mast is provided with the required rigidity through the use of cross bracing 4' secured to the legs and disposed therebetween, said cross bracing, as shown in Fig. 3, being extended through the entire height of the leg structure of the mast from bottom to top thereof.

Supported by the leg structure of the mast at the upper end thereof is the crown B of the improved mast, said crown comprising a pair of opposed substantially parallel side-beams 5 which are connected together atth-eir opposite ends by suitable end beams 6. The rectangular structure produced by the opposed side beams 5 and the end beams 6 is provided with the required rigidity by tie rods 1 which are attached at their opposite ends to upstanding elements 8 which are fixed to the opposed side beams 5, and said rectangular structure is disposed in a substantially horizontal position at the top of the mast with the longitudinal center of the rectangular structure of the crown in substantial vertical alinement with respect to the longitudinal axis of the leg structure of the mast. The mast includes suitable means 9 for attaching the rectangular structure of the crown B of said mast to the leg structure thereof, and said leg structure is inclined upwardly from the cross beam 3 toward the axis of the hole being drilled as shown in Fig. 1, wherein the broken line C indicates said axis of the hole Supported by the opposed side beams 5 of the crown B of the improved mast is a pair of spaced apart shafts I and II, said shafts being substantially equidistant in opposite directions from the axis of the leg structure of the mast. The shaft l0 supports for rotation a pair of sheaves l2 and the shaft ll supports for rotation a pair of larger sheaves l3. The shafts l0 and Il may be supported fixedly by the side beams of the crown B of the mast with the sheaves rotatably mounted thereon, or, if desired, said shafts may be rotatably supported with the sheaves fixed to the shafts for rotation therewith. Operating over the sheaves l2 and I3, which constitute the crown block of the mast, is a drilling line l4 and associated with said drilling line in accordance with the usual block and tackle arrangement is a traveling block IS. The traveling block I5 is shown in the drawing in diagrammatical form, as its construction forms no part of the invention, it being understood, however, that the traveling block employed with the improved mast is provided with the usual hook for engaging the Kelly joint associated with the drill stem. It is also understood that one end of the drilling line is dead ended in the usual manner, while the other end portion of said drilling line extends to the draw works (not shown) which is operable to wind or unwind the drilling line with respect to a drum to raise or lower the drill stem. The mast A has associated therewith guys l6 which aid in supporting the mast.

In the use of the improved mast disclosed herein the load carried by the mast is distributed at the upper end of the leg structure of the mast. This results from the fact that the crown B of the mast is so disposesd with respect to the upper end of the leg portion of the mast that its weight is substantially balanced relative to said upper end of the leg portion of the mast. Asa matter of fact the use of the larger sheaves [3 causes the peripheral edges of said larger sheaves at the end of the crown opposed to the end at which the load is suspended to be further removed from the axis of the leg structure of the mast than are the outer edges of the smaller sheaves II. By so arranging the crown of the mast with respect to the leg structure thereof the operation of the drilling line over the crown block provided by the sheaves of the crown causes the strain produced by the load carried by the mast to be imparted largely longitudinally of the leg structure of the mast. Thus because the load carried by the mast is supported to a large degree by the leg structure of the mast the strains previously imparted to the guys of masts of the construction formerly used are very substantially reduced. Also because of the use of the overhanging Itype of crown which causes the drilling line to be located largely outwardly of a position between the legs of the mast the cross bracing of the leg structure of the mast may be extended throughout the entire height of said leg structure of the mast.

I claim:

1. A mast for drilling oil wells and the like comprising supporting means, a leg structure supported by said supporting means and composed of a pair of spaced legs, said legs being anchored to said supporting means at their lower ends at one side of the location of a hole to be drilled with the aid of the mast and being inclined so that the upper portion of the leg structure approaches a vertically alined position with respect to the location of the hole, guy cables for retaining said leg structure in its inclined position, a crown disposed in a substantially horizontal plane at the upper end of said leg structure so that it overhangs said upper end portion of said leg structure in opposite directions, spaced shafts supported by said crown at opposite sides of the upper portion of said leg structure, sheaves mounted on said shafts, a drilling line operating over said sheaves and having a continuous part extended downwardly from said sheaves with portions of said downwardly extended continuous part of the drilling line being extended downwardly from sheaves at both sides of the upper portion of the leg structure, and a traveling block supported for operation by said downwardly extended continuous part of the drilling line.

2. A mast for drilling oil wells and the like comprising supporting means, a leg structure supported by said supporting means and composed of a pair of spaced legs which converge from bottom to top, said legs being anchored to said supporting means at their lower ends at one side of the location of a hole to be drilled with the aid of the mast and being inclined so that the upper portion of the leg structure approaches a vertically alined position with respect to the location of the hole, guy cables for retaining said leg structure in its inclined position, a crown disposed in a substantially horizontal plane at the upper end of said leg structure so that it overhangs said upper end portion of said leg structure in opposite directions, spaced shafts supported by said crown at opposite sides of the upper portion of said leg structure, sheaves mounted on said shafts, a drilling line operating over said sheaves and having a continuous part extended downwardly from said sheaves with portions of said downwardly extended continuous part of the drilling line being extended downwardly from sheaves at both sides of the upper portion of the leg structure, and a traveling block supported for operation by said downwardly extended continuous part of the drilling line.

3. A mast for drilling oil wells and the like comprising supporting means, a leg structure supported by said supporting means and composed of a pair of spaced legs which converge from bottom to top, said legs being anchored to said supporting means at their lower ends at one side of the location of a hole to be drilled with the aid of the mast and being inclined so that the upper portion of the leg structure approaches a vertically alined position with respect to the location of the hole, guy cables for retaining said leg structure in its inclined position, a

- crown disposed in a substantially horizontal plane at the upper end of said leg structure so that it overhangs said upper end portion of said leg structure in opposite directions, said crown comprising a substantially rectangular structure, spaced shafts supported by said crown at opposite sides of the upper portion of said leg structure, sheaves mounted on said shafts, a drilling line operating over said sheaves and having a continuous part extended downwardly from said sheaves with portions of said downwardly extended continuous part of the drilling line being extended downwardly from sheaves at both sides of the upper portion of the leg structure, and a traveling block supported for operation by said downwardly extended continuous part of the drilling line.

4. A mast for drilling oil wells and the like comprising supporting means, a leg structure supported by said supporting means and composed of a pair of spaced legs which converge from bottom to top, said legsbeing anchored to said supporting means at their lower ends at one side of the location of a hole to be drilled with the aid of the mast and being inclined so that the upper portion of the leg structure approaches a vertically alined position with respect to the location of the hole, guy cables for retaining said leg structure in its inclined position, a

crown disposed in a substantially horizontal plane at the upper end of said leg structure so that it overhangs said upper end portion of said leg structure in opposite directions, said crown comprising a substantially rectangular structure, spaced shafts supported by said crown at opposite sides of the upper portion of said leg structure, pairs of sheaves mounted on said shafts, the pair of sheaves mounted on one of said shafts being of larger diameter than the pair of sheaves mounted on the other shaft, a drilling line operating over said sheaves and having a continuous part extended downwardly from said sheaves with portions of said downwardly extended continuous part of the drilling line being extended downwardly from sheaves at both sides of the upper portion of the leg structure, and a traveling block supported for operation by said downwardly extended continuous part of the drilling line.

DEE MILLER. 

